The present invention relates to an electronic timepiece having multi-functions and particularly relates to a program memory namely an address driving system of ROM.
Recently, according to a development of IC-manufacturing technique, a timepiece system having a ROM-RAM system has appeared on the market. Thereby, one is able to make a timepiece having many kinds of functions by applying the ROM-RAM system to the timepiece, such as a world time timepiece, a stopwatch, a timer timepiece, an alarm timepiece and a calculating timepiece.
In the prior art of Japanese Laid Open Patent Specification No. 85861/77 (which corresponds to U.S. Pat. No. 4,063,409), a timepiece system having multi-functions is disclosed wherein, an address proceeding of a RAM is prosecuted in synchronization to a timepiece address counter or chronograph address counter. Therefore, it basically differs from an address renewal as a program memory, and a circuit construction of this prior art is composed of a RAM and a operational PLA which is operated by the contents of the counter which is operated in synchronization to 1/10 sec. Therefore, the contents of the address counter is changed every 1/10 second whereby a minimum counting unit as a stopwatch only becomes 1/10 second. Namely, in the conventional type, another 1/100 second counter is prepared in IC as another counter which is separate from the normal time counter.